1. Field of the Invention
This invention relates to heat-dissipating means, and more particularly, to a windblown-type heat-dissipating device for use on a circuit board, such as a computer mother board, for the purpose of dissipating heat produced from the circuit components on the circuit board.
2. Description of Related Art
During the operation of a circuit board, such as a computer mother board, heat can be produced from some circuit components, such as the CPU (central processing unit), that if not properly dissipated, can cause damage to their internal circuitry. A conventional way of dissipating the heat from a CPU is to mount a heat-conductive member on the CPU and then use an air-sucking means to cause an air stream to flow over the heat-conductive member such that the heat from the CPU can be dissipated. This conventional way of dissipating heat from a CPU is illustratively depicted in the following with reference to FIG. 2.
As shown in FIG. 1, the conventional heat-dissipating device includes an electric fan 1, an air inlet 2, a heat-conductive member 4, and an air outlet 5. The CPU is mounted beneath the heat-conductive member 4. The electric fan 1 and the air outlet 5 are provided in one sidewall 32 of the casing 3 of the computer, while the air inlet 2 is provided in the other sidewall 31 of the casing 3. When the electric fan 1 is being operated, it can suck the cool air from the outside through the air inlet 2 to flow over the heat-conductive member 4 and then drain out to the outside through the air outlet 5. The flowing air can thus bring the heat on the heat-conductive member 4 from the CPU to the outside, thereby maintaining the CPU at a low temperature. One drawback to the foregoing heat-dissipating device, however, is that part of the air being sucked in through the air inlet 2 can be diverted away from the CPU to an area indicated by A in FIG. 2 instead of flowing to the area B where the CPU is mounted. This is because that the path from the air inlet 2 via the area A to the air outlet 5 is shorter than the path from the air inlet 2 via the CPU and then via the electric fan 1 to the air outlet 5. Since this part of the incoming cool air will not contribute to the cooling of the CPU, the overall heat-dissipating efficiency is considerably low. This drawback not only causes the electric fan 1 to waste more electric power, but also causes the CPU to be easily subjected to damage since the heat-dissipating efficiency is inadequate.